Method and apparatus for forming and collecting fibers into an improved pipe covering

Claim 1

IN THE FORMATION OF A GENERALLY CYLINDRICAL FIBROUS CASING HAVING SUBSTANTIALLY UNIFORM THICKNESS WHEREIN SAID GENERALLY CYLINDRICAL FIBROUS CASING IS NOT CONFINED WITHIN MOLDS DURING THE CURING OF THE BINDER THEREIN, THE METHOD COMPRISING: (A) FORMING ON A MANDREL A GENERALLY CYLINDRICAL FIRBOUS CASING OF SUSBTANTIALLY UNIFORM THICKNESS IMGREGNATED THROUGHOUT WITH UNCURED HEAT-CURABLE BINDER. (B) APPLYING SUFFICIENT HEAT TO THE PERIPHERAL SURFACE OF SAID FIBROUS CASING BY CONTACTING SAID PERIPHERAL SURFACE WITH A HOT BODY TO CONTACT CURE THE BINDER IMMEDIATELY ADJACENT SAID PERIPHERAL SURFACE TO FORM A SUBSTANTIALLY RIGID SHELL ON SAID FIBROUS CASING PRODUCING A FIBROUS CASING OF SUBSTANTIALLY UNIFORM THICKNESS ON WHICH SAID RIGID SHELL PROVIDES A SUBSTANTIALLY CYLINDRICAL EXTERNAL PERIPHERY, (C) SEPARATING SAID FIBROUS CASING AND SAID HOT BODY, (D) CURING THE BINDER IN THE REMAINING PORTIONS OF SAID FIBROUS CASING WITHOUT CONFINING THE FIBROUS CASING IN A MOLD AND WHILE MAINTAINING AT LEAST PORTIONS OF THE SHELL FREELY EXPOSED, AND (E) RELYING UPON SAID SUBSTANTIALLY RIGID SHELL TO MAINTAIN THE EXTERNAL SHAPE AND THE SUBSTANTIALLY UNIFORM THICKNESS OF SAID FIBROUS CASING DURING SAID CURING OF THE BINDER IN SAID REMAINING PORTIONS OF SAID FIBROUS CASING.